Ground effects machine with airflow directing nozzles



Sept. 17,1968 J.D. ;ULL 3,401,768

GROUND EFFECTS MACHINE WITH AIRFLOW DIRECTING NOZZLES Filed Sept. 21,1966' s Sheets-Sheet 1 5 l l I I l l l WI I :3 a \i I \i I l I l I I l II l I a l l 0 I Q I i I E i I l l I Q i I I I a Joseph 0. Cull INVENTOR.

\I n & v a BY k WW 1i M5 INVEN TOR.

3 Sheets-Sheet 2 J. D. cum.

GROUND EFFECTS MACHINE WITH AIRFLOW DIRECTING NOZZLES Sept. 17, 1968Filed Sept. 21, 1966 WEGEM Se t. 17, 1968 J. D. cuu. 3,401,753

GROUND EFFECTS MACHINE WITH AIRFLOW DIRECTING NOZZLES 3 Sheets-Sheet 5Filed Sept. 21, 1966 Joseph D. Cull INVENTOR.

BY M

United States Patent 3,401,768 GROUND EFFECTS MACHINE WITH AIRFLOWDIRECTING NOZZLES Joseph D. Cull, 3508 Longview Ave., Bloomington, Ind.47401 Filed Sept. 21, 1966, Ser. No. 580,986 13 Claims. (Cl. 180-122)ABSTRACT OF THE DISCLOSURE A G.E.M. utilizing a diffuser-nozzle systemwherein pressurized air is directed outwardly through a series ofincreasing area passages to the periphery of the vehicle andsubsequently discharged downwardly through aligned nozzle air passagesof rapidly decreasing'cross-sectional area thereby producing, inaddition to a vehicle lifting pressure, a substantial thrust to effect agreater lift. The nozzles are of a rigid fixed area and shapeconstruction with selected one of the nozzles being pivotally adjustableso as to vary the direction of the constant thrust being dischargedtherefrom for use of this thrust as a balance and guidance control.

The instant invention relates to new and useful improvements in groundeffects machines, and is particularly concerned with achieving acombination of greater lift and increased guidance and propulsioncapabilities.

It is a primary object of the instant invention to provide a groundeffects machine wherein the lift is achieved through a combination ofpressure build-up and high velocity thrust.

In conjunction with the above object, it is also a significant object ofthe instant invention to provide a G.E.M. wherein a single fan orpropeller is utilized with the moving air generated thereby being sodirected as to provide the desired combination of lifting pressure andthrust in conjunction with the guidance and propulsion desired in such acraft.

Another significant object of the instant invention is the provision ofa system wherein a diffuser-nozzle arrangement is utilized with the areaof the individual flow passages being initially increased so as to causea corresponding pressure increase and velocity decrease, andsubsequently rapidly decreased so as to result in a velocity increasewhich in turn produces a thrusting effect desired, the vena contractabeing produced forward of the discharge end of the decreasing area.

Further, it is a significant object of the instant invention to utilizeelongated discharge nozzles which, in addition to providing the desiredthrust in conjunction with the pressure build-up, are also capable ofbeing directionally adjusted so as to be utilized in effecting theguidance and propulsion of the G.E.M.

Furthermore, it is a significant object of the instant invention toprovide a device which is equally adaptable for utilization inconjunction with both large and small vehicles with the constructionitself being relatively simple and economically feasible.

In conjunction with the above object, it is also an important object ofthe instant invention to provide a device wherein the control systemutilizes the air discharge nozzles themselves in a manner whichcomplements the basic simplicity of the device.

Basically, in order to achieve the above objects, it is an intention ofthe instant invention to construct a G.E.M. incorporating a lift unitdefined by upper and lower spaced parallel panels in conjunction with aplurality of elongated vertically orientated braces positionedtherebetween and both engaging the panels and maintaining therelationship therebetween so as to define an internal chamber havingseparate flow paths. The chamber is communicated with a source ofpressurized air through an enlarged generally centrally located openingprovided through the upper panel, the braces radiating outward from theperiphery of the circular opening and diverging from each other so as toform air paths or diffusers having exit ends at the periphery of thelift unit substantially greater than the entry ends adjacent the openingperiphery. In this manner, as the air travels outward through theincreasing area of the diffusers, the velocity of the air flow decreasesalong with a corresponding pressure increase. At the outer edges of thediffusers, this being at the outer edges of the lift unit itself, aplurality of depending nozzles are provided for effecting a downwarddirecting of the air flow. These nozzles decrease in area from enlargedentry ends directly communicated with the exit ends of the correspondingdiffusers to the exit ends thereof whereby a velocity increase iseffected so as to produce the vena contracta at a maximum distance fromthe nozzle exits or discharges. In this manner, not only does theparticular craft hover as a result of the pressure build uptherebeneath, but, through the thrust developed by the rapidly exitingair, a substantially greater lift to the vehicle or craft results.Selected ones of the discharge nozzles are to be movably mounted wherebya guiding of the craft is possible merely through a manipulation of thedischarging nozzle itself. A further feature of the lift unit is theprovision of specific means for maintaining a sealed chamber between thehorizontal diffusers and the vertical nozzles throughout the range ofmovement of the movable ones of the nozzles, this consisting ofselectively scalable flaps responsive to the flow of air itself.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a reduced partial side elevational view of a G.E.M.incorporating the lift unit of the present invention;

FIGURE 2 is an enlarged top plan view, partially in section, of the liftunit;

FIGURE 3 is a vertical cross-sectional view taken substantially on aplane passing along line 33 with the propeller driving engine or motordisclosed schematically;

FIGURE 4 is a top perspective view, partially broken away, of the liftunit;

FIGURE 5 is a perspective detail of the construction of the nozzles anddiffusers, along with the joining area therebetween;

FIGURE 6 is a cross-sectional detail of one type of control means forthe front and rear nozzles; and

FIGURE 7 is an elevational view, partially broken away, illustrating onetype of control means that can be used in conjunction with the forwardside nozzles.

Referring now more specifically to the drawings, reference numeral 10 isused to generally designate the ground effects machine comprising theinstant invention. The actual lift unit of the G.E.M. 10 is designatedby reference numeral 12, while the body of the machine 10 is hereindesignated by reference numeral 14.

Referring specifically to the lift unit 12, as best illustrated inFIGURES 2-5, it will be noted that this unit 12 includes enlarged upperand lower flat panels 16 and 18 retained in spaced parallel relation toeach other by a plurality of vertically orientated smooth surfaced flatelongated braces 20. In this manner an enlarged divided internal chamberis provided between the panels 16 and 1-8. The upper panel 16 isprovided with an enlarged circular opening 22 therein, which may beprovided with a flange or housing wall 24 thereabout. This Opening 22,located at a specified point inward of the periphery of the lift unit12, is provided as an entry means for forced or pressurized air whichwill originate from a power driven fan or propeller 26 mounted eitherwithin or immediately above the opening 22 as generally indicated inFIGURES 2 and 3. The bottom panel 18 is of course imperforate, andincludes a smooth inner surface as does the upper panel 16-.

The vertical braces 28, noting FIGURES 2 and 4 in particular, extendradially outward from the periphery of the top panel opening 22 in amanner so as to define a plurality of radially extending airflowpassages which increase in area outward from the intake or entry endthereof at the periphery of the opening 22 to the outlet or exit endthereof at the outer edges of the panels 16 and 18 which define theperiphery of the lift unit 12. In this manner, inasmuch as a subsonicfluid flow is involved, a plurality of diffusers are defined wherein apressure increase and a corresponding velocity decrease is experiencedas the airflow moves outward through the increasing area toward theouter edges of the unit 12. Incidentally, it will be noted that theouter end portions of the braces 20 are angularly directed so as toapproach the outer edges of the panels 16 and 18 at right anglesthereto, these braces 20 extending beyond the corresponding edges so asto overlie the various vertically orientated airflow directing nozzlesassociated with the unit 12.

The nozzles are of three basic types, front and rear adjustablepropelling nozzles 28 and 30, side forward adjustable guiding orsteering nozzles 32 and 34, and side rear fixed nozzles 36 and 38. Allof the nozzles 28-38 of course contribute to the lift, with thepropelling and guidance functions being effected through slightadjustments of the corresponding nozzles so as to vary the direction ofthe discharging thrust from the vertical.

The construction of all of the nozzles 28-38 is generally similar andconsists of a plurality of flat downwardly converging braces 40 and 42,in conjunction with inner and outer facing panels 44 and 46. The nozzlebraces 40 are associated with the movable nozzles 28, 30, 32, and

34 and are accordingly hingedly pivoted, as at 48, to the projectingends of the corresponding panel braces 20 so as to depend verticallytherefrom. The nozzle braces 42 depend in the same direction as thenozzle braces 40, however, the braces 42 are rigidly mounted on theouter ends of the corresponding panel braces 20 so as to be immovablerelative thereto. The inner and outer panels 44 and 46 associated withthe movable nozzles 28, 30, 32, and 34 are secured directly to theassociated braces 40 for pivotal movement either inwardly or outwardlyaway from the vertical. It will be noted that the front and rear nozzles28 and extend across the entire width of the unit 12 and incorporateseveral braces therein corresponding to the braces 20 communicating withthe particular edge whereby the braces 40 effectively definecontinuations of the fluid paths of the chamber between the panels 16and 18. The movable nozzles 32 and 34 are positioned on the oppositesides of the unit 10 and extend rearwardly for a distance from the frontof the unit 12, the front of the unit being that end having the nozzle28 mounted thereon. These side guiding nozzle 32 and 34 will generallycorrespond to the front wheels of an automobile in their steeringfunction and can be of any desired length, such being illustrated asencompassing the exit or discharge ends of two diffusers. The fixednozzles 36 and 38, utilizing the rigidly mounted braces 42, extendrearwardly from the two steering nozzles 32 and 34 to the rear end ofthe unit 12 and operate solely to provide lift.

All of the nozzle braces 40 and 42, and thereby the nozzles 28-38themselves, have a downwardly tapered configuration whereby the entryends thereof communicated directly with the discharge ends of thediffusers, are substantially wider than the downwardly opening dischargeor exit ends. Thus, the subsonic flow of air, due to the decreasing areain the nozzles, experiences a rapid increase in velocity so as to effecta substantial thrust which will increase the lift or clearance obtainedfrom the builtup pressure beneath the unit.

I11 order to provide for a leak-free passage of the air from eachdiffuser to the corresponding nozzle passage defined between the nozzlebraces 40, upper and low sealing flaps 50 and 52 are utilized. The lowerflap 52 has the inner edge portion thereof permanently fixed, as bygluing, to the adjacent edge portion of the lower panel 18 and extendstherefrom into received relation within the corresponding nozzlepassage, the outer edge of the flap 52 being fully received within thenozzle passage. The fiap 50 is secured, as by adhesive, to the innersurface of an arcuate cowling or the like 54 which is aflixed to theupper surface of the upper panel 16 and arcs over the rounded outer endsof the panel braces 20. This flap 50 continues downwardly from the outeredge of the cowling 54 into free received relation within thecorresponding nozzle passage. Thus, as the pressurized air flows fromthe diffuser through the corresponding nozzle passage, the pressure andflow will force the free outer or lower portions of the flaps 50 and 52into sealed engagement with the inner and outer nozzle panels 44 and 46so as to effect an air tight flexible joint therebetween which allowsfor the adjustment of the nozzles 28-34 while maintaining the desiredseal. These flaps 50 and 52, which are of course flexible and air tight,can be formed of rubber or any suitable plastic such as neoprene.Further, it should be appreciated that the cowling 54 is to be somounted as to allow for the free pivotal movement of the nozzles 28-34within the range contemplated therefor. Inasmuch as the nozzles 36 and38 are to be fixed, any suitable permanent seal can be provided betweenthe nozzle panels 44 and 46 and the corresponding upper and lower panels16 and 18.

The front and rear nozzles 28 and 30 are to be individually controlledwith this control being effected in any desirable manner, such as thepneumatic system sug gested in FIGURE 6. In this system, a pneumatictube 56 extends through the upper and lower panels 16 and 18 and has alower laterally directed portion which receives a plunger 58 having theouter end thereof pivotally ,engaged with the inner face of the nozzle,and a laterally directed upper end portion having a plunger 60 thereinand projected therefrom for pivotal engagement with a control lever 62.Such a control system, or an equivalent thereof, will be associated withboth the front and rear nozzles 28 and 30.

The side guiding or steering nozzles 32 and 34 are to be simultaneouslycontrolled for synchronized movement. FIGURE 7 illustrates onesimplified type of control system utilizing a control lever 64 having apair of oppositely extending cables 66 fixed thereto and extending aboutmounted pulleys 68 into engagement with the outer panels 46 of thenozzles 32 and 34. Another cable or link 70 is engaged between the innerfaces of the nozzles 32 and 34, thereby providing for a simultaneouspivoting of the nozzles 32 and 34 upon a manipulation of the lever 64.

Depending upon the particular use to which the G.E.M. is to be put,various types of floats, wheels, skids, etc., can be associatedtherewith, the recessed corners defined between the adjacent nozzles atthe corners of the unit 12 defining convenient wheel wells.

In actual use, the propeller or fan 26 is activated so as to force airthrough the circular opening 22 and into the chamber defined between theupper and lower flat panels 16 and 18. This pressurized air flowsoutward through the smooth wall diffusers, defining by the panels 16 and18 and the braces 20. Since a subsonic fluid flow is involved, and theinlet area of each of the diffusers at the circular opening 22 is lessthan the outlet area at the periphery of the units 12, the pressure atthe outlet area is substantially greater than at the inlet area. The airflow, as it leaves the chambers, follows the path defined by the smoothflexible sealing flaps 50 and 52 and into the upper inlet ends of thenozzles 28-68, the sealing flaps 50 and 52 because of the pressure ofthe air, being forced outwardly into sealing engagement with thecorresponding nozzle panels 44 and 46 so as to effect a positive airseal therewith regardless of the position of the particular nozzle. Thearea of the nozzles decreases downwardly with the area at the exit endsof the nozzles being'less than that at the entry ends of the nozzles soas to result in a substantial increase in the velocity of the fluidflow. The increased velocity creates a thrust along the nozzle axis andaway from the nozzle. The thrust from the nozzles significantly adds tothe lift from pressure build-up under the lift unit so as to result in asubstantial increase in the lift or clearance as compared to that whichwould be obtained were build-up pressure alone relied upon in boldingthe craft in a hovering position above the surface. Thus, it should beappreciated that not only is the G.E.M. lifted through the utilizationof built up pressure asis commonly effected, but in addition asignificant additional lift is achieved through the utilization ofdirect thrust produced by a high velocity discharge resulting from adiffuser-nozzle system. Further, through a pivotal mounting of the frontand rear nozzles 28 and 30, as well as the forward side nozzles 32 and34, a slight variation in the vertical positioning thereof will enable,utilizing the same flow of air, both a propelling of the device eitherforward or rearward, and a steering or guiding of the device. Thedesirability of having individual controls for the front and rearnozzles 28 and 30 is that, through a manipulation of one or the other,independent of the second, a balancing of the craft will be possibleshould an unbalanced load or the like be introduced thereon. Also, itmight at this time be pointed out that various nozzle arrangements,other than that specifically illustrated, are also contemplated withinthe scope of the instant invention. As an example, one form of G.E.M.incorporating the features of this invention is to include adjustablerear side nozzles operative in conjunction with the adjustable frontside nozzles, and in the opposite direction, so as to effect a tighterturning of the craft.

From the foregoing, it should be appreciated that, utilizing a singlepropeller or fan as a source for forced air, the instant inventioncontemplates the provision of a ground effects machine which has asubstantially greater lift capability than conventional G.E.M.s, as wellasboth a guidance and propulsion means utilizing the same air flow. Thethrust utilized in the device of the instant invention, so as to providethe additional lift, is achieved through the provision of a diffusernozzle arrangement wherein the flow of air is initially taken through aprogressively increased area which results in a corresponding pressureincrease and subsequently is directed through a rapid decreased area soas to effect a corresponding rapid increase in velocity immediatelyprior to discharge toward the surface over which the device is to besupported. When constructing a device in accordance with the instantinvention, it will be appreciated that the nozzle will be so designed asto position the vena contracta of the discharging flow of air, thisbeing the point of maximum contraction of the flow and thereby the pointof greatest velocity, at a maximum distance from the outlet of thenozzles so as to in turn obtain the maximum thrust. As noted supra, itis this thrust, in combination with the built up pressure, whereby thegreater lift is achieved, in conjunction with improved degree ofmobility.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. In a ground effects machine, a lift unit, and an air flow inducingmeans, said unit defining a plurality of diffusers, each diffuser havingan intake end and an outlet end, said air flow inducing means being inflow passing communication with the intake ends of the diffusers, theoutlet ends of said diffusers being orientated peripherally about saidunit, and downwardly directed nozzles having intake ends in flowreceiving communication with the diffuser outlet ends, said diffusersincreasing in area between the intake and outlet ends thereof, resultingin an air velocity decrease and a corresponding pressure increase, saidnozzles continuously decreasing in area between the intake and outletends thereof, resulting in a velocity increase and the forming of acorresponding vena contracta outward of the nozzles, said unit includingvertically spaced upper and lower rigid flat panels, and elongated rigidbraces affixed between said panels, said panels and said braces definingthe diffusers therebetween, said nozzles depending from the unit aboutthe periphery of said panels, said nozzles each comprising a pluralityof rigid brace members, and inner and outer rigid panel members mountedon said brace members and converging downwardly, said brace membersconstituting substantially coplanar continuations of said braces wherebyindividual flow passages extend continuously from the diffuser intake tothe nozzle outlet.

2. The machine of claim 1 wherein said upper panel has a circularopening defining through a central portion thereof, said air flowinducing means discharging downward through said opening, the intakeends of said diffusers being orientated peripherally about said opening,said braces, and thereby said diffusers, projecting radially therefromto the periphery of said panels, said braces and brace members beingirnperforate.

3. The machine of claim 2 including means defining a sealed passagebetween each diffuser and the corresponding nozzle, the panels, asidefrom the circular opening in the upper panel, and the panel membersbeing imperforate.

4. The machine of claim 3 wherein selected ones of said nozzles areadjustably mounted for varying the position of the outlet ends thereofand effecting a guidance of the unit, and means for adjusting theadjustable nozzles, said adjustable nozzles maintaining a constantcross-section, area, and outlet end size throughout the range ofadjustment.

5. In a ground effects machine, a lift unit, and an air flow inducingmeans, said unit defining a plurality of diffusers, each diffuser havingan intake end and an outlet end, said air flow inducing means being inflow passing communication with the intake ends of the diffusers, theoutlet ends of said diffusers being orientated peripherally about saidunit, and downwardly directed nozzles having intake ends in flowreceiving communication with the diffuser outlet ends, said diffusersincreasing in area between the intake and outlet ends thereof, saidnozzles decreasing in area between the intake and outlet ends thereof,said unit including vertically spaced upper and lower flat panels, andelongated braces afiixed between said panels, said panels and saidbraces defining the diffusers therebetween, said air flow inducing meanscommunicating with the diffusers through an opening in one of saidpanels; the intake ends of said diffusers being orientated peripherallyabout said opening, said diffusers projecting outwardly therefrom to theperiphery of said panels, said nozzles depending from the unit about theperiphery of said panels, said nozzles each comprising a plurality'ofbrace members, and inner and outer panel members mounted on said bracemembers and converging downwardly, and means defining a sealed passagebetween each diffuser and the corresponding nozzle, selected ones ofsaid nozzles being adjustably mounted for varying the position of theoutlet ends thereof and effecting a guidance of the unit, and means foradjusting the adjustable nozzles, said sealed passage defining meanscomprising a pair of flexible flaps fixed to the upper and lower panelsand depending freely into the corresponding nozzle adjacent the innerand outer panel members for sealing engagement thereagainst in responseto internal air pressure created by the flow of air therebetween.

6. The machine of claim wherein said unit has front and rear ends andopposed sides, said adjustable nozzles be mounted on the front and rearends and on the forward portions of the opposed sides.

7. In a ground effects machine, a lift unit, and an air flow inducingmeans, said unit defining a plurality of diffusers, each diffuser havingan intake end and an outlet end, said air flow inducing means beingbeing in flow passing communication with the intake ends of thediffusers, the outlet ends of said diffusers being orientatedperipherally about said unit, and downwardly directed nozzles havingintake ends in flow receiving communication with the diffuser outletends, said diffusers increasing in area between the intake and outletends thereof, said nozzles decreasing in area between the intake andoutlet ends thereof, said unit including vertically spaced upper andlower fiat panels, g

and elongated braces are fixed between said panels, said panels and saidbraces defining the diffusers therebetween, said upper panel having acircular opening defined through a central portion thereof, said airflow inducing means discharging downwardly through said opening, theintake ends of said diffusers being orientated peripherally about saidopening, said diffusers projecting radially therefrom to the peripheryof said panels, said nozzles depending from the unit about the peripheryof said panels, said nozzles each comprising a plurality of braces, andinner and outer panel members mounted on said brace members andconverging downwardly, and means defining a sealed passage between eachdiffuser and the corresponding nozzle, said sealed passage definingmeans comprising a pair of flexible flaps fixed to the upper and lowerpanels and depending freely into the corresponding nozzle adjament theinner and outer panel members for sealing engagement thereagainst inresponse to internal air pressure created by the flow of airtherebetween.

8. In a ground effects machine, a lift unit, said unit comprising upperand lower coextensive panels, elongated vertically orientated bracesaffixed between said panels and maintaining said panels in spacedrelation to each other, an air flow introducing opening defined throughone of said panels, said braces extending outwardly from said opening tothe periphery of said unit and defining a plurality of air passagesprogressively increasing in area outward from the opening, a pluralityof nozzles depending from the periphery of the unit and defining aseparate air passage in alignment with each of said first-mentioned airpassages, and means communicating each nozzle air passage with acorresponding one of said first-mentioned air passages at the peripheryof the unit in an air passing manner, said nozzle air passagesprogressively decreasing in area downward from the communicated airpassages to the outlet ends thereof.

9. The machine of claim 8 wherein said unit has a front end and a rearend, said nozzles being rigid and defining nozzle air passages of fixedcross-section and area, one of said nozzles being substantiallycoextensive with each end and adjustable thereon for selective movementof the corresponding nozzle air passage outlet ends either forward orrearward relative to the vertical so as to vary the direction ofdischarge therefrom, said adjustable nozzle air passages maintainingtheir fixed cross-section and area throughout the adjustment thereof.

10. The machine of claim 8 wherein each nozzle, and hence the airpassages defined thereby, is of a continuously decreasingcross-sectional area to the outlet end thereof.

11. The machine of claim 8 wherein the facing surfaces of said upper andlower coextensive panels are parallel, said panels being rigid, saidvertically orientated braces between said coextensive panels being rigidand imperforate.

12. In a ground efiects machine, a lift unit, and unit comprising upperand lower rigid coextensive panels defining a generally horizontalconstant height chamber therebetween, rigid elongated verticallyorientated braces sealed between said panels, an air flow introducingopening defined through one of said panels, said braces extendingoutwardly from said opening to the periphery of said unit in divergingrelation to each other so as to definite a plurality of closed airpassages progressively increasing in area outwardly from the opening tothe periphery of the unit, a plurality of nozzles depending from theperiphery of said unit, each nozzle being defined by downwardlyconverging spaced rigid panels and rigid lateral brace members sealedtherebetween, each of said nozzle brace members being substantiallycoplanar with a corresponding brace so as to define a nozzle air passagein direct alignment with each of said first-mentioned air passages, saidnozzle air passages progressively decreasing in area to outlet ends dueto the convergence of the associated nozzle panels, said nozzle airpassages being in direct air receiving communication with saidfirst-mentioned air passages whereby a substantially straight line flowof air is effected from the air introducing opening to the nozzle airpassage outlet ends at which point a thrust producing discharge iseffected.

13. The machine of claim 12 wherein selective ones of said nozzles arerotatably adjustable about the adjoining portion of the periphery of theunit while maintaining the size and shape of all the involved airpassages and changing only the direction of the constant thrustproducing discharging air.

References Cited UNITED STATES PATENTS 3,170,276 2/1965 Hall -7 X3,170,530 2/1965 Black 180-7 3,175,785 3/1965 De Tore et al 180-7 X3,182,627 5/1965 Rethorst 180-7 X 3,244,246 4/1966 Weiland. 3,272,271 9/1966 Cookerell. 3,291,236 12/1966 Foshag et a1.

FOREIGN PATENTS 1,008,930 11/ 1965 Great Britain.

A. HARRY LEVY, Primary Examiner.

